<template>
    <div class="todo-footer" v-show="total">
        <label>
            <!-- <input type="checkbox" :checked='isAll' @change = 'checkAll'/> -->
            <input type="checkbox" v-model="isAll"/>
        </label>
        <span>
            <span>已完成{{doneTotal}}</span> / 全部{{total}}
        </span>
        <button class="btn btn-danger" @click="clearAll">清除已完成任务</button>
    </div>
</template>

<script>
    export default {
        name:'MyFooter',
        props:['todos'],
        computed:{
            total(){
                return this.todos.length
            },
            // doneTotal(){
            //     return this.todos.reduce((pre,current)=>{
            //         return pre+(current.done?1:0)
            //     },0)
            // },

            doneTotal(){
                return this.todos.reduce((pre,todo)=>pre+(todo.done ? 1 : 0),0)
            },
            isAll:{
                // 全选框是否勾选
                get(){
                    return this.doneTotal === this.total && this.total > 0
                },
                // isAll被修改时set被调用
                set(value){
                    this.$emit('checkAllTodo',value)
                } 
            }
        },
        methods:{
            // checkAll(e){
            //     console.log(e.target.checked)
            //     this.checkAllTodo(e.target.checked)
            // },
            clearAll(){
                this.$emit('clearAllTodo')
            }
        }
    }
 
</script>

<style>
    /*footer*/
    .todo-footer {
        height: 40px;
        line-height: 40px;
        padding-left: 6px;
        margin-top: 5px;
    }

    .todo-footer label {
        display: inline-block;
        margin-right: 20px;
        cursor: pointer;
    }

    .todo-footer label input {
        position: relative;
        top: -1px;
        vertical-align: middle;
        margin-right: 5px;
    }

    .todo-footer button {
        float: right;
        margin-top: 5px;
    }
</style>
